Try to answer this just by making a sketch, without doing any calculations: Which random variable has greater expected value: the distance from (1,0) to a random point on the circle x^2 + y^2 = 4, or the distance from (2,0) to a random point on the circle x^2 + y^2 = 1? And: which random variable has greater variance? Please post no answers until February 28. Jim Propp